3D underwater topography rebuilding based on single beam sonar

In this paper we rebuild the 3D underwater topography of an experimental pool using single beam sonar. Compared with other sensors like multi-beam sonar and some other optical devices single beam sonar is cheap and small. And we choose the open source 3D model and animation software Blender as our modeling platform. In our experiment the sonar follows a straight line to get 2D slices of the underwater environment and then we combine these 2D slices together to get the 3D point cloud. Then we use several filters and segmentation methods to process the 3D point cloud to make it smooth. Finally we build the underwater model based on the processed 3D point cloud using the covering method we created, which comes from the idea that when you cover a table with a moldable table cloth, the table cloth will be in the shape of the table. We carry out the experiment in two different underwater places in an experimental pool. The experimental results show that the covering method can build models with reliable shapes and sizes.